The present invention relates to a device for applying small quantities of fluid to a surface such as the surface of a microscope slide. Heretofore, microscope slide preparation by the spinning technique required at least 250.mu.L of blood to assure full coverage of the slide surface with a blood film or layer. This amount of blood is readily available if a venipuncture is performed on a patient. However, in many cases, particularly pediatrics, venipuncture is not desirable, and small volumes, typically 100.mu.L maximum, of blood are drawn from a superficial skin puncture of the fingertip, heel, or earlobe. With such small quantities of blood it has heretofore been difficult to obtain a uniform layer of blood of sufficient thickness to permit a good blood slide for microscopic examination to be formed by the spinning process. Blood slides may be formed by applying a quantity of blood to the surface of a microscope slide and thereafter spinning it in a slide centrifuge such as that described in U.S. patent application Ser. No. 363,433 filed May 24, 1973, now U.S. Pat. No. 3,906,890, by L. G. Amos et al. and assigned to a common assignee with the present application.